Question: Simplify the following expression: $k = \dfrac{5t^2 - 6st}{2rt + t} - \dfrac{rt}{2rt + t}$ You can assume $r,s,t \neq 0$.
Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{5t^2 - 6st - (rt)}{2rt + t}$ $k = \dfrac{5t^2 - 6st - rt}{2rt + t}$ The numerator and denominator have a common factor of $t$, so we can simplify $k = \dfrac{5t - 6s - r}{2r + 1}$